“The bottom line is that before, all IOS exploits had to know the exact IOS image running on the target to get code execution. This is approximately a 1 to 100,000 chance, [and] a professional attacker doesn’t risk his 0-day exploit when the odds are stacked against him like that,” Linder says. “I [demonstrated] that at least on one group of Cisco routers, there is a way to execute code without knowing the IOS image version [they are] running.”